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DOE OSTI2025

Abbreviated Report for 25-FS-011: Switch and Stitch Similar Subgraph Synthesizer

Government institutions utilize software from a wide array of development sources, including those written by large software companies, government contractors, and open-source repositories. Avoiding installation of malicious software components is an important national security endeavor. Automated analysis of previously unseen software is an active research area, and there is much research in the design of systems that compare new software artifacts to a large set of previously seen software records organized by various behaviors they contain. One attractive approach is to turn each compiled software binary into a graph representation and apply a graph similarity model that scores pairs of binaries by their relative similarity. When a pair is deemed similar, it is useful to know why, in the sense of providing explanations to security analysts regarding which portions of the software they should look into further.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

DOE OSTI2025

Corral Summit Pumped Storage Hydropower Hybrid: Site Suitability Assessment

In 2024, Idaho National Laboratory (INL) and Pacific Northwest National Laboratory (PNNL) initiated a technical-assistance project to support Cat Creek Energy, LLC, (CCE) in evaluating site suitability for the proposed Corral Summit Pumped Storage Hydropower (PSH) project in south-central Idaho near Mackay Reservoir. The Corral Summit facility incorporates battery storage and photovoltaic (PV) solar arrays in a Trybrid configuration to deliver large-volume long-duration (LVLD) storage solutions for rural electric cooperatives in eastern Idaho. The evaluation process focused on determining the most-suitable location for the upper reservoir of the PSH system, guided by a comprehensive assessment framework spanning multiple categories, including physical characteristics, environmental constraints, building infrastructure, regulatory constraints, cultural resources and sensitivity, social factors, and power market and grid integration. Each site was analyzed based on a ranking scale (0–1), which scores ranging from “severely disfavored” to “highly favored,” allowing detailed comparisons of site-specific conditions. Categories such as hydraulic head, utilities corridor, land ownership, and transmission-grid limitations emerged as key contributors to the overall assessment. Site 2 (Idaho Trust) demonstrated a slight advantage over Site 1 (Bureau of Land Management) primarily due to favorable outcomes in regulatory constraints, building infrastructure, and power-market integration. However, Site 1 outperformed Site 2 in factors related to physical characteristics and social factors. The report emphasizes the need for further evaluation of both sites before clear determination of which site is preferred, due to the limited information available on either site at the time of this report. Key areas of evaluation to clearly define the preferred site are ecological impacts, cultural-resource surveys, and economic-feasibility assessments. For successful project execution, recommended follow-up actions include seismic and geotechnical surveys, groundwater and habitat monitoring, regulatory reviews of water rights and right-of-way agreements, cultural engagement with local tribal governments, and enhanced stakeholder strategies. These efforts will ensure the Corral Summit Trybrid facility meets local energy needs while balancing environmental, social, and regulatory responsibilities.

13 - HYDRO ENERGY↗

DOE OSTI2025

Corral Summit Pumped Storage Hydropower Hybrid Site Suitability Assessment (Rev.1)

13 - HYDRO ENERGY↗

DOE OSTI2018

Stellar Parameters and Radial Velocities of Hot Stars in the Carina Nebula

The Carina Nebula is an active star-forming region in the southern sky that is of particular interest due to the presence of a large number of massive stars in a wide array of evolutionary stages. Here, we present the results of the spectroscopic analysis of 82 B-type stars and 33 O-type stars that were observed in 2013 and 2014. For 82 B-type stars without line blending, we fit model spectra from the Tlusty BSTAR2006 grid to the observed profiles of Hγ and He λλ4026, 4388, and 4471 to measure the effective temperatures, surface gravities, and projected rotational velocities. We also measure the masses, ages, radii, bolometric luminosities, and distances of these stars. From the radial velocities measured in our sample, we find 31 single lined spectroscopic binary candidates. We find a high dispersion of radial velocities among our sample stars, and we argue that the Carina Nebula stellar population has not yet relaxed and become virialized.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2026

A 3D-Printed Millimeter-Wave Inline Waveguide-to-Coplanar-Waveguide Transition to Enable Dense Spectrometer Arrays for Intensity Mapping Surveys

We present a 3D-printed millimeter-wave, octave-bandwidth, in-line waveguide-to-coplanar-waveguide transition designed to enable focal planes with dense arrays of on-chip spectrometers. These arrays will enable compelling surveys of the large-scale structure of the universe through millimeter-wave intensity mapping. The transition consists of a four-step ridge-waveguide transformer that couples light from a rectangular waveguide onto a coplanar waveguide via an electrical connection made with indium bump bonds. We develop a tolerance-aware optimization approach to identify high-performance transition geometries that are robust to manufacturing variations; the same formulation can be applied to other tolerance-sensitive design problems. We also describe the implementation of a custom apparatus and procedure for bump-bonding a silicon chip to a metallized 3D-printed component. We detail the fabrication of the coplanar waveguide chip and three-dimensional waveguide structure, simulations and metrology of a test device, and room temperature reflectance measurements of this device. The room temperature metrology and reflection measurements are consistent with a model that predicts a coupling efficiency of $\mathord{\sim} 95\%$ at cryogenic temperatures in the 85-170 GHz frequency range.

Stover, Austin [Chicago U.; Chicago U., KICP] (ORC↗

DOE OSTI2026

Locating the missing large-scale emission in the jet of M87* with short EHT baselines

In very-long baseline interferometric arrays, nearly co-located stations probe the largest scales and typically cannot resolve the observed source. In the absence of a large-scale structure, closure phases constructed with these stations are zero and, since they are independent of station-based errors, they can be used to probe data issues. Here, we show how these trivial closure phases become nonzero with a brightness distribution on smaller scales than their short baseline would suggest. When applied to sources that are made up of a bright compact and large-scale diffuse component, the trivial closure phases directly measure the centroid relative to the compact source and higher-order image moments. We present a technique to measure these image moments with minimal model assumptions and validate it on synthetic Event Horizon Telescope (EHT) data. We then apply this technique to 2017 and 2018 EHT observations of M87* and find a weak preference for extended emission in the direction of the large-scale jet. We also apply it to 2021 EHT data and measure the source centroid about 1 mas northwest of the compact ring, which is consistent with the jet observed at lower frequencies.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2017

In-situ preparation of Fe{sub 2}O{sub 3} hierarchical arrays on stainless steel substrate for high efficient catalysis

Hierarchical array catalysts with micro/nano structures on substrates not only possess high reactivity from large surface area and suitable interface, but intensify mass transfer through shortening the diffusion paths of both reactants and products for high catalytic efficiency. Herein, we first demonstrate fabrication of Fe{sub 2}O{sub 3} hierarchical arrays grown on stainless-steel substrates via in-situ hydrothermal chemical oxidation followed by heat treatment in N{sub 2} atmosphere. As a Fenton-like catalyst, Fe{sub 2}O{sub 3} hierarchical arrays exhibit excellent catalytic activity and life cycle performance for methylene blue (MB) dye degradation in aqueous solution in the presence of H{sub 2}O{sub 2}. The Fe{sub 2}O{sub 3} catalyst with unique hierarchical structures and efficient transport channels, effectively activates H{sub 2}O{sub 2} to generate large quantity of • OH radicals and highly promotes reaction kinetics between MB and • OH radicals. Immobilization of hierarchical array catalysts on stainless-steel can prevent particles agglomeration, facilitate the recovery and reuse of the catalysts, which is expected promising applications in wastewater remediation. - Graphical abstract: The in-situ synthesis of Fe{sub 2}O{sub 3} hierarchical arrays on stainless-steel substrates was reported for the first time, which exhibit excellent catalytic activity performance for methylene blue (MB) dye degradation in aqueous solution in the presence of H{sub 2}O{sub 2}. - Highlights: • Fe{sub 2}O{sub 3} hierarchical arrays was prepared by in-situ hydrothermal chemical oxidation. • F{sup −} ions play an important role in the formation of the Fe{sub 2}O{sub 3} hierarchical arrays. • Fe{sub 2}O{sub 3} hierarchical arrays show high catalytic activity to methylene blue degradation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2016

Method to Determine Maximum Allowable Sinterable Silver Interconnect Size

The use of sintered-silver for large-area interconnection is attractive for some large-area bonding applications in power electronics such as the bonding of metal-clad, electrically-insulating substrates to heat sinks. Arrays of different pad sizes and pad shapes have been considered for such large area bonding; however, rather than arbitrarily choosing their size, it is desirable to use the largest size possible where the onset of interconnect delamination does not occur. If that is achieved, then sintered-silver's high thermal and electrical conductivities can be fully taken advantage of. Toward achieving this, a simple and inexpensive proof test is described to identify the largest achievable interconnect size with sinterable silver. The method's objective is to purposely initiate failure or delamination. Copper and invar (a ferrous-nickel alloy whose coefficient of thermal expansion (CTE) is similar to that of silicon or silicon carbide) disks were used in this study and sinterable silver was used to bond them. As a consequence of the method's execution, delamination occurred in some samples during cooling from the 250 degrees C sintering temperature to room temperature and bonding temperature and from thermal cycling in others. These occurrences and their interpretations highlight the method's utility, and the herein described results are used to speculate how sintered-silver bonding will work with other material combinations.

30 DIRECT ENERGY CONVERSION↗

DOE OSTI2013

ASGARD: A LARGE SURVEY FOR SLOW GALACTIC RADIO TRANSIENTS. I. OVERVIEW AND FIRST RESULTS

Searches for slow radio transients and variables have generally focused on extragalactic populations, and the basic parameters of Galactic populations remain poorly characterized. We present a large 3 GHz survey performed with the Allen Telescope Array (ATA) that aims to improve this situation: ASGARD, the ATA Survey of Galactic Radio Dynamism. ASGARD observations spanned two years with weekly visits to 23 deg{sup 2} in two fields in the Galactic plane, totaling 900 hr of integration time on science fields and making it significantly larger than previous efforts. The typical blind unresolved source detection limit was 10 mJy. We describe the observations and data analysis techniques in detail, demonstrating our ability to create accurate wide-field images while effectively modeling and subtracting large-scale radio emission, allowing standard transient-and-variability analysis techniques to be used. We present early results from the analysis of two pointings: one centered on the microquasar Cygnus X-3 and one overlapping the Kepler field of view (l = 76 Degree-Sign , b = +13. Degree-Sign 5). Our results include images, catalog statistics, completeness functions, variability measurements, and a transient search. Out of 134 sources detected in these pointings, the only compellingly variable one is Cygnus X-3, and no transients are detected. We estimate number counts for potential Galactic radio transients and compare our current limits to previous work and our projection for the fully analyzed ASGARD data set.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2014

A two dimensional silicon detectors array for quality assurance in stereotactic radiotherapy: MagicPlate-512

Purpose: Silicon diode arrays are commonly implemented in radiation therapy quality assurance applications as they have a number of advantages including: real time operation (compared to the film) and high spatial resolution, large dynamic range and small size (compared to ionizing chambers). Most diode arrays have detector pitch that is too coarse for routine use in small field applications. The goal of this work is to characterize the two-dimensional monolithic silicon diode array named “MagicPlate-512” (MP512) designed for QA in stereotactic body radiation therapy (SBRT) and stereotactic radio surgery (SRS). Methods: MP512 is a silicon monolithic detector manufactured on ap-type substrate. An array contains of 512 pixels with size 0.5 × 0.5 mm{sup 2} and pitch 2 mm with an overall dimension of 52 × 52 mm{sup 2}. The MP512 monolithic detector is wire bonded on a printed circuit board 0.5 mm thick and covered by a thin layer of raisin to preserve the silicon detector from moisture and chemical contamination and to protect the bonding wires. Characterization of the silicon monolithic diode array response was performed, and included pixels response uniformity, dose linearity, percent depth dose, output factor, and beam profiling for beam sizes relevant to SBRT and SRS and depth dose response in comparison with ionization chamber. Results: MP512 shows a good dose linearity (R{sup 2} = 0.998) and repeatability within 0.2%. The measured depth dose response for field size of 10 × 10 cm{sup 2} agreed to within 1.3%, when compared to a CC13 ionization chamber for depths in PMMA up to 30 cm. The output factor of a 6 MV Varian 2100EX medical linac beam measured by MP512 at the isocenter agrees to within 2% when compared to PTW diamond, Scanditronix point EDD-2 diode and MOSkin detectors for field sizes down to 1 × 1 cm{sup 2}. An over response of 4% was observed for square beam size smaller than 1 cm when compared to EBT3 films, while the beam profiles (FWHM) of MP512 match to within 2% the data measured by radiochromic film. Conclusions: The response of the 2D detector array, MP512, has been evaluated. The properties of the array demonstrated suitability for use as in phantom dosimeter for QA in SRS and SBRT. Although MP512 matches film measurements down to 1 × 1 cm{sup 2} well, it showed a discrepancy of 4% in the determination of output factors of beams smaller than 0.5 × 0.5 cm{sup 2} due to the field perturbation generated by the large amount of silicon surrounding the central diode. MP512 is highly capable of measuring beam size (FWHM) and has a discrepancy of less than 1.3% when compared to EBT3 film. A reduction in the detector pitch to less than 2 mm would improve the penumbra reconstruction accuracy at the cost readout electronics complexity.

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2019

Lu-Hf isotopic evidence of a deep mantle plume source for the ~2.06 Ga Bushveld Large Igneous Province

The Bushveld Large Igneous Province (B-LIP) comprises a diverse array of >30 magma bodies that intruded the Kaapvaal Craton at ~2.06 Ga. Here, we use zircon and bulk-rock Lu-Hf isotope data to determine whether the B-LIP formed in response to the arrival of a plume(s) from the deep mantle or by melting of the depleted upper mantle during foundering of an eclogitized residue at the base of the lithosphere. New zircon Hf isotope compositions for four B-LIP bodies yield intrusion-specific average εHf (2.06Ga) values that range from -20.7 ± 2.8 to -2.7 ± 2.8, largely consistent with literature zircon data for other B-LIP intrusions. Bulk-rock solution εHf (2.06Ga) values for a variety of B-LIP intrusions range from -2.1 ± 0.2 to -10.6 ± 0.2. Because the most radiogenic Hf isotope compositions across the entire B-LIP are nearly primordial, having an εHf (2.06Ga) close to 0, it is likely that the heat source of the B-LIP was a plume(s) from deep mantle. The Hf isotope data further indicates that individual intrusions in the B-LIP were produced by melting of three distinct source reservoirs (in addition to melts derived from the plume itself): 1) Subduction and plume modified continental lithospheric mantle; 2) Older (~2.7 Ga) mafic-ultramafic plume-related material trapped in the Kaapvaal lithosphere; and 3) Mid- to upper Kaapvaal crust. The presence of ~2.7 Ga mafic-ultramafic material in the Kaapvaal lithosphere may have acted to strengthen the lithosphere so that it was able to resist being dispersed by the arrival of the B-LIP plume at ~2.06 Ga.

58 GEOSCIENCES↗

DOE OSTI2013

Fast, Low Noise Photodetectors for Nuclear Physics

The overall goal of the Phase-II project was to construct and evaluate high performance SSPM technology for nuclear physics experiments. To achieve this overall objective, we first undertook optimization of the SSPM technology. This effort involved further enhancement of the optical quantum efficiency as well as the geometric efficiency (or fill-factor) of the SSPMs, which resulted in improvement of the photodetection efficiency of the SSPMs. Important SSPM parameters such as gain, dark count-rate, cross-talk, temporal response, after-pulsing, quantum efficiency and photodetection efficiency were evaluated for the optimized devices and these parameters were compared with those for Phase-I prototypes. Large area SSPMs (1 to 2 cm 2 ) were built using optimal design parameters. Noise analysis of large area SSPMs was performed. Upon coupling SSPMs to various scintillators (LSO/LYSO, LaBr 3 :Ce, NaI:Tl, LuAG:Ce etc.), energy resolution studies were carried. Timing resolution was also be measured with SSPMs coupled to fast scintillators (such as LaBr 3 :Ce, BaF 2 , LuAG:Ce, plastic and LSO/LYSO) using 511-keV gamma-rays ( 22 Na source). Multi-element SSPM arrays (6 x 6 format with ~1.5 x 1.5 mm 2 elements) were also designed and built using the CMOS process. These SSPM arrays were packaged and appropriate readout electronics was assembled. These SSPM arrays were operated with individual readout of each SSPM element. Large area (~1 cm 2 ) micro-pixel level PS-SSPMs with active and passive components to enable on-chip charge sharing for position sensing were also designed and built. Spatial, energy and timing resolution studies were conducted with the multi-element SSPM arrays as well as PS-SSPMs coupled to segmented scintillation arrays.

99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2022

Phenylene-linked tetrapyrrole arrays containing free base and diverse metal chelate forms – Versatile synthetic architectures for catalysis and artificial photosynthesis

Tetrapyrrole macrocycles are central to photosynthesis yet a single macrocycle does not carry out photosynthesis; rather, assemblies of tetrapyrrole macrocycles work in concert in antenna complexes, reaction centers, and electron-transport chains to harvest sunlight, funnel excited-state energy and separate charge for biological use. A longstanding theme in artificial photosynthesis has been to construct covalently linked “arrays” of metalated and free base tetrapyrrole macrocycles for fundamental studies of such processes, which entail excited-state and ground-state interactions. Among linkers in arrays chemistry, the 1,2-, 1,3-, or 1,4-disubstituted phenylene unit has proved very attractive owing to the resulting short distance, defined architecture, and appropriate extent of electronic coupling of adjacent macrocycles to give rapid electron and/or energy transfer while largely retaining desired spectral features. Eight distinct strategies to construct phenylene-linked tetrapyrrole arrays are identified in a review with comprehensive coverage since inception in the early 1970s through mid-year 2021. The arrays predominantly incorporate porphyrins with very few chlorins and bacteriochlorins, reflecting historic availability of synthetic methods for macrocycle formation. Of the eight strategies, only two appear applicable to (bacterio)chlorins. While studies in artificial photosynthesis have largely fueled this field, applications in catalysis have also been examined. Altogether >400 arrays are covered. The review delves into synthesis and molecular design, sketches photophysical properties, and suggests unrealized opportunities in arrays chemistry.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2012

Porous SiC nanowire arrays as stable photocatalyst for water splitting under UV irradiation

Highlights: Black-Right-Pointing-Pointer Arrays of porous SiC nanowires prepared by a facile in situ carbonizing method. Black-Right-Pointing-Pointer Utilizing the SiC nanowire arrays as photocatalysis for water splitting. Black-Right-Pointing-Pointer Excellent photocatalytic performance under the UV irradiation. Black-Right-Pointing-Pointer Very high stability of the SiC nanowire photocatalyst. -- Abstract: In this study, we report the fabrication and photocatalytic properties of the oriented arrays of SiC nanowires on the Si substrate. The SiC nanowire arrays were prepared by carbonizing the Si nanowire arrays with the graphite powder at 1250 Degree-Sign C. The as-prepared SiC nanowires are highly porous, which endows them with a high surface-to-volume ratio. Considering the large surface areas and the high stability, the porous SiC nanowire arrays were used as photocatalyst for water splitting under UV irradiation. It was found that such porous SiC structure exhibited an enhanced and extremely stable photocatalytic performance.

36 MATERIALS SCIENCE↗

DOE OSTI2024

The IEA Wind Task 49 Reference Floating Wind Array Design Basis

International Energy Agency Wind Technology Collaboration Programme (IEA Wind) Task 49 on Integrated Design of Floating Wind Arrays is an international collaboration aiming to advance the development of large-scale floating wind farms by providing open-access resources to the research and development and planning communities. The work of Task 49 focuses on array-level challenges related to the colocation of many floating wind turbines; their layouts, mooring systems, and cabling systems; failure risks; logistical considerations; marine spatial planning needs; and future research needs and innovation directions. This report provides a general design basis for the development of reference floating wind farm designs. These reference array designs will extend the scope of existing reference floating wind turbine designs to facilitate research on array-level floating wind technology challenges and innovations. The design basis promotes coordination and consistency in developing the reference array designs.

17 WIND ENERGY↗

DOE OSTI2017

Vertically Integrated Edgeless Photon Imaging Camera

The Vertically Integrated Photon Imaging Chip - Large, (VIPIC-L), is a large area, small pixel (65μm), 3D integrated, photon counting ASIC with zero-suppressed or full frame dead-time-less data readout. It features data throughput of 14.4 Gbps per chip with a full frame readout speed of 56kframes/s in the imaging mode. VIPIC-L contain 192 x 192 pixel array and the total size of the chip is 1.248cm x 1.248cm with only a 5μm periphery. It contains about 120M transistors. A 1.3M pixel camera module will be developed by arranging a 6 x 6 array of 3D VIPIC-L’s bonded to a large area silicon sensor on the analog side and to a readout board on the digital side. The readout board hosts a bank of FPGA’s, one per VIPIC-L to allow processing of up to 0.7 Tbps of raw data produced by the camera.

Fahim, Farah↗

DOE OSTI2013

Sub-grid drag models for horizontal cylinder arrays immersed in gas-particle multiphase flows

Immersed cylindrical tube arrays often are used as heat exchangers in gas-particle fluidized beds. In multiphase computational fluid dynamics (CFD) simulations of large fluidized beds, explicit resolution of small cylinders is computationally infeasible. Instead, the cylinder array may be viewed as an effective porous medium in coarse-grid simulations. The cylinders' influence on the suspension as a whole, manifested as an effective drag force, and on the relative motion between gas and particles, manifested as a correction to the gas-particle drag, must be modeled via suitable sub-grid constitutive relationships. In this work, highly resolved unit-cell simulations of flow around an array of horizontal cylinders, arranged in a staggered configuration, are filtered to construct sub-grid, or `filtered', drag models, which can be implemented in coarse-grid simulations. The force on the suspension exerted by the cylinders is comprised of, as expected, a buoyancy contribution, and a kinetic component analogous to fluid drag on a single cylinder. Furthermore, the introduction of tubes also is found to enhance segregation at the scale of the cylinder size, which, in turn, leads to a reduction in the filtered gas-particle drag.

Computational fluid dynamics (CFD), Cylinders, Fil↗

DOE OSTI2012

Design and operation of the wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source

The wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source (SNS) is optimized to provide a high neutron flux at the sample position with a large solid angle of detector coverage. The instrument incorporates modern neutron instrumentation, such as an elliptically focused neutron guide, high speed magnetic bearing choppers, and a massive array of {sup 3}He linear position sensitive detectors. Novel features of the spectrometer include the use of a large gate valve between the sample and detector vacuum chambers and the placement of the detectors within the vacuum, both of which provide a window-free final flight path to minimize background scattering while allowing rapid changing of the sample and sample environment equipment. ARCS views the SNS decoupled ambient temperature water moderator, using neutrons with incident energy typically in the range from 15 to 1500 meV. This range, coupled with the large detector coverage, allows a wide variety of studies of excitations in condensed matter, such as lattice dynamics and magnetism, in both powder and single-crystal samples. Comparisons of early results to both analytical and Monte Carlo simulation of the instrument performance demonstrate that the instrument is operating as expected and its neutronic performance is understood. ARCS is currently in the SNS user program and continues to improve its scientific productivity by incorporating new instrumentation to increase the range of science covered and improve its effectiveness in data collection.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗